The efficacy of photodynamic therapyi st ypically reliant on the local concentration and diffusion of oxygen. Due to the hypoxic microenvironment found in solid tumors, oxygen-independent photosensitizers are in great demand for cancer therapy. We herein report an iridium(III) anthraquinone complex as am itochondrion-localized carbon-radical initiator.I ts emission is turned on under hypoxic conditions after reduction by reductase.F urthermore,i ts two-photon excitation properties (l ex = 730 nm) are highly desirable for imaging.U pon irradiation, the reduced form of the complex generates carbon radicals,l eading to al oss of mitochondrial membrane potential and cell death (IC 50 light = 2.1 mm,IC 50 dark = 58.2 mm,P I= 27.7). The efficacy of the complex as aP DT agent was also demonstrated under hypoxic conditions in vivo. To the best of our knowledge,i ti st he first metal-complexbased theranostic agent which can generate carbon radicals for oxygen-independent two-photon photodynamic therapy.
Background Coronary artery atherosclerosis is a chronic inflammatory disease. This study aimed to identify the key changes of gene expression between early and advanced carotid atherosclerotic plaque in human. Methods Gene expression dataset GSE28829 was downloaded from Gene Expression Omnibus (GEO), including 16 advanced and 13 early stage atherosclerotic plaque samples from human carotid. Differentially expressed genes (DEGs) were analyzed. Results 42,450 genes were obtained from the dataset. Top 100 up- and downregulated DEGs were listed. Functional enrichment analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) identification were performed. The result of functional and pathway enrichment analysis indicted that the immune system process played a critical role in the progression of carotid atherosclerotic plaque. Protein-protein interaction (PPI) networks were performed either. Top 10 hub genes were identified from PPI network and top 6 modules were inferred. These genes were mainly involved in chemokine signaling pathway, cell cycle, B cell receptor signaling pathway, focal adhesion, and regulation of actin cytoskeleton. Conclusion The present study indicated that analysis of DEGs would make a deeper understanding of the molecular mechanisms of atherosclerosis development and they might be used as molecular targets and diagnostic biomarkers for the treatment of atherosclerosis.
The mechanisms and enantioselectivities of the dirhodium (Rh2L4, L = formate, N-methylformamide, S-nap)-catalyzed intramolecular C-H aminations of 3-phenylpropylsulfamate ester have been investigated in detail with BPW91 density functional theory computations. The reactions catalyzed by the Rh2(II,II) catalysts start from the oxidation of the Rh2(II,II) dimer to a triplet mixed-valent Rh2(II,III)-nitrene radical, which should facilitate radical H-atom abstraction. However, in the Rh2(formate)4-promoted reaction, as a result of a minimum-energy crossing point (MECP) between the singlet and triplet profiles, a direct C-H bond insertion is postulated. The Rh2(N-methylformamide)4 reaction exhibits quite different mechanistic characteristics, taking place via a two-step process involving (i) intramolecular H-abstraction on the triplet profile to generate a diradical intermediate and (ii) C-N formation by intersystem crossing from the triplet state to the open-shell singlet state. The stepwise mechanism was found to hold also in the reaction of 3-phenylpropylsulfamate ester catalyzed by Rh2(S-nap)4. Furthermore, the diradical intermediate also constitutes the starting point for competition steps involving enantioselectivity, which is determined by the C-N formation open-shell singlet transition state. This mechanistic proposal is supported by the calculated enantiomeric excess (94.2% ee) with the absolute stereochemistry of the product as R, in good agreement with the experimental results (92.0% ee).
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